肺高分辨率CT马赛克样灌注与小气道功能指数的相关分析

目的探讨肺小气道病变时高分辨率CT（HRCT）所示马赛克样灌注与小气道功能指标的相关性。方法选择HRCT上显示马赛克样灌注病例80例,由3位放射诊断医师对马赛克样灌注与小气道功能指标的相关性进行分析。结果马赛克样灌注与FEF 25%呈负相关（r=-0.48,P〈0.05）,与FEV1、FEF50%无相关性（r值分别为-0.27和-0.19,P〉0.05）。而空气潴留的程度与FEF25%、FEV1呈负相关（r值分别为-0.62和-0.41,P〈0.05）,与FEF 50%无相关性（r=-0.29,P〉0.05）。结论马赛克样灌注作为小气道病变的主要征象,其与FEF 25%具有良好的相关性,而空气潴留作为小气道阻塞的直接后果,其程度与FEV1、FEF 25%具显著相关性,即使肺功能检查结果正常时,也可以辅助诊断临床可疑的小气道阻塞。     

Cardiorespiratory responses to submaximal incremental exercise are not affected by one night's sleep deprivation during the follicular and luteal phases of the menstrual cycle

The purpose of the study was to investigate the effects of one night's sleep deprivation on the cardiorespiratory responses to exercise during the follicular and luteal phases of the menstrual cycle. We have studied nine, healthy females aged 24-35 years with regular menstrual cycles. Each subject performed spirometric tests at rest and then an incremental exercise testing during 11-13 days of follicular phase and 22-24 days of luteal phase following one normal night's sleep or one night's sleep loss. Compared with resting values exercise produced significant increases in cardiorespiratory variables including oxygen uptake (VO2), carbon dioxide production (VCO2), tidal volume (VT), respiratory rate (RR), minute ventilation (VE), systolic blood pressure, heart rate (HR) and respiratory quotient (R). However, it did not alter significantly diastolic blood pressure, end-tidal PO2 (PETO2), end-tidal PCO2 (PETCO2) and arterial oxygen saturation (SaO2). Spirometric variables which include forced vital capacity (FVC), forced expiratory volume in one s (FEV1), FEV1/FVC%, forced expiratory volume in three s (FEV3), forced expired flow from 25-75% of FVC (FEF 25-75%), forced expired flow at 25% of FVC (FEF 25%), forced expired flow at 50% of FVC (FEF 50%), forced expired flow at 75% of FVC (FEF 75%), forced expired flow from 75-85% of FVC (FEF 75-85%), peak expiratory flow (PEF), expiratory reserve volume (ERV), inspiratory capacity (IC) and maximal voluntary ventilation (MVV) and cardiorespiratory variables were not different between the cycle phases after one normal night's sleep or one night's sleep deprivation. Neither menstrual cycle phase nor sleep deprivation affected spirometric and cardiorespiratory parameters. We suggest that one night's sleep deprivation does not produce alterations in spirometric parameters and cardiorespiratory responses to submaximal incremental exercise during the follicular and luteal phases.     

小气道功能指标在儿童哮喘病情严重程度评估及临床诊断中的应用

目的 探讨小气道功能指标在儿童哮喘病情严重程度评估及临床诊断中的应用价值。方法 选取2013年5月至2016年4月于郑州市第二人民医院56例哮喘急性发作期病儿作为哮喘组,并根据哮喘急性发作严重程度分为轻度(21例)、中度(20例)和重度(15例)三个亚组,同时选取同期、年龄相仿及性别相匹配的30例因其他原因引起喘息咳嗽的慢性炎症病儿和32例入院检查健康儿童分别作为非哮喘组和对照组,收集各组儿童一般资料,采用肺功能测定系统检测各组儿童用力肺活量(FVC)、最大呼气流量(PEF)、第1秒用力呼气容积(FEV1)和FEV1/FVC比值、呼出25%肺活量时呼气流速(FEF25%)、呼出50%肺活量时呼气流速(FEF50%)、呼出75%肺活量时呼气流速(FEF75%)、最大中期呼气流速(MMEF)等指标。结果 与对照组比较,非哮喘组和哮喘组病儿FVC、FEV1、PEF、FEF25%、FEF50%、FEF75%和MMEF等指标均显著降低(P<0.05),且哮喘组病儿上述指标显著低于非哮喘组[(1.42±0.36)L比(1.85±0.47)L、(1.25±0.32)L比(1.42±0.41)L、(2.68±0.64)L比(3.25±0.77)L/s、(2.54±0.65)L/s比(3.74±0.68)L/s、(1.58±0.36)L/s比(2.24±0.71)L/s、(0.61±0.37)L/s比(1.02±0.41)L/s、(1.42±0.49)L/s比(1.89±0.68)L/s)](均P<0.05),而三组病儿FEV1/FVC指标差异无统计学意义(P>0.05)。哮喘急性发作期不同程度病儿用力呼出25%肺活量的呼气流量占预计值百分比(FEF25pred%)、用力呼出50%肺活量的呼气流量占预计值百分比(FEF50pred%)、用力呼出75%肺活量的呼气流量占预计值百分比(FEF75pred%)、最大呼气中期流量占预计值的百分比(MMEFpred%)等指标比较差异有统计学意义(P<0.05),且随着病情程度增加,病儿FEF25pred%、FEF50pred%、FEF75pred%、MMEFpred%等指标呈现明显降低趋势(P<0.05),FEF25%和FEF75%指标在不同严重程度哮喘病儿中异常率比较,差异有统计学意义(P<0.05),FEF50%和MMEF指标比较差异无统计学意义(P>0.05),其中FEF25%主要表现为轻度异常,而FEF75%主要表现为重度异常。结论 小气道功能指标在儿童哮喘病情严重程度评估及临床诊断具有重要意义,随着病情加剧,小气道功能指标明显降低,且异常率显著增加。     

Procaterol metered aerosol in patients with chronic obstructive pulmonary disease

The activity and tolerability of procaterol, a recently introduced beta 2-adrenergic drug, were evaluated in comparison with fenoterol and a placebo in a single blind, cross-over study, using a metered aerosol formulation. Twelve patients suffering from chronic obstructive pulmonary disease with reversible bronchial obstruction were enrolled. Before and 30, 120, 240, 360, 480 min after drug administration, forced vital capacity (FVC), forced expiratory volume at the first second, forced expiratory flow at 25-75% and 75-85% respectively of the FVC, thoracic gas volume and the specific airways conductance were calculated. Procaterol 20 mcg showed a significant bronchodilating activity as well as fenoterol 400 mcg. This activity was already significant within 30 min, achieved its maximum after two hours and lasted more than eight hours. Side-effects were complained of by 41% of patients treated with procaterol and by 50% treated with fenoterol; procaterol showed less cardiovascular effects than fenoterol.     

Chronically inhaled salmeterol improves pulmonary function in heart failure

Inhaled beta-agonists are commonly prescribed for the symptoms of exercise intolerance in heart failure despite a paucity of data regarding their safety and efficacy. This was a prospective, randomized, double-blind, double-dummy, placebo-controlled 14-day cross-over study to determine if chronic inhaled salmeterol therapy 84 microg every 12 hours improved pulmonary function without augmentation of neurohormonal systems or ventricular ectopy in 8 symptomatic heart failure subjects with left ventricular ejection fraction (LVEF) <40% and FEV1 相似文献   

Longitudinal study of lung function development in a cohort of Indian medical students: interaction of respiratory allergy and smoking

This study was done to identify some factors that affect the growth and development of lung function during adolescence and early adulthood. Forced expiratory spirograms and peak expiratory flow rates were obtained in a cohort of normal young men (n = 63) over a period of 4 years, at intervals of approximately 2 years. Two factors that disturbed the normal pattern of lung function development in this group were smoking and respiratory allergy. Among the smokers and the allergics the decline in the forced expiratory volume expressed as a percentage of the forced vital capacity (FEV1%), the forced expiratory flow in the middle half of the forced vital capacity (FEF25-75%) and the FEF25-75% expressed as a ratio of the forced vital capacity (FEF/FVC) was more than double that among the normal subjects. The number of smokers and of allergics increased during the course of the study from 15 to 19 and from 16 to 23 respectively. There was a significant (P less than .01) interaction between smoking and the manifestation of respiratory allergy. Among nonsmokers, the number of allergic subjects increased from 12 to 13, while among smokers it increased from 4 to 10, during the four years.     

Determination of %FVC (FEV/FVC%) at expiratory flow rate of 1 lit/sec and 0.5 lit/sec from forced expiratory spirogram

A method for determination of %FVC (FEV/FVC%) at forced expiratory flow rate (FEF) of 1 lit./sec. and 0.5 lit/sec from the forced expiratory spirogram is described. This parameter is simpler to determine and is a better expression of end expiratory flow rate than FEF 75%-85%.     

支气管肺泡灌洗联合甲泼尼龙琥珀酸钠辅助治疗难治性肺炎支原体 肺炎疗效及对肺功能的影响

目的:探讨支气管肺泡灌洗(BAL)联合甲泼尼龙琥珀酸钠辅助治疗难治性肺炎支原体肺炎(RMPP)的临床疗效及对肺 功能的影响。方法:选取2021 年1 月至2022 年6 月在我院儿童呼吸科住院并诊断为RMPP 的患儿96 例。根据是否行 BAL 分 为激素治疗组(n =42)和联合治疗组(n =54),激素治疗组采用常规大环内酯类药物抗感染基础上加用小剂量甲泼尼龙琥珀酸 钠治疗;联合治疗组在激素治疗组的基础上加用BAL。比较两组患儿咳嗽改善时间、体温恢复正常时间、肺部体征明显吸收好 转时间、住院时间及肺部影像学吸收情况,并对入院时肺功能和出院1 个月后肺功能进行分析。结果:治疗后,联合治疗组的总 有效率为96. 30%,激素治疗组为80. 95%,差异有统计学意义(P<0. 05)。联合治疗组的咳嗽改善时间、体温恢复正常时间、肺 部体征明显吸收时间、住院时间、胸部影像学吸收效果优于激素治疗组( P <0. 05)。96 例RMPP 患儿中肺功能异常91 例 (94. 79%),其中49 例为混合性通气功能障碍(49/ 96,51. 04%),25 例为阻塞性通气功能障碍(25/ 96,26. 04%),11 例为小气道 功能障碍(11/ 96,11. 46%),6 例为限制性通气功能障碍(6/ 96,6. 25%)。入院时两组患儿肺功能指标呼气峰流量( PEF)、第1 秒用力呼气容积(FEV1)、用力呼气流量(FEF)25%、FEF50%、FEF75%、最大呼气中期流量(MMEF)、用力肺活量(FVC) 水平比 较,差异无统计学意义(P>0. 05)。但出院后1 个月两组患儿肺功能指标比较,差异有统计学意义(P<0. 05),联合治疗组的肺 功能改善更明显。结论:BAL 联合甲泼尼龙琥珀酸钠治疗RMPP 相比单用甲泼尼龙琥珀酸钠治疗,具有更好的临床疗效和更 快的病灶吸收速度;超过90%的RMPP 患儿存在肺功能异常,其中以混合性通气功能异常最常见,其次是阻塞性通气功能异 常。通过BAL 可加速肺功能的改善,促进肺功能恢复。     

The effect of tiotropium on the pulmonary diffusing capacity

To our knowledge, there is no data on the effect of tiotropium on pulmonary gas exchange in healthy subjects. The aim of this study was to assess the effects of tiotropium on pulmonary diffusing capacity. Twenty-one healthy volunteers were enrolled for a prospective, randomized, double-blind, placebo-controlled study. Spirometric measurements, including pulmonary-diffusing capacity, were obtained before and after inhalation of drug or placebo. There was a significant decrease in forced vital capacity (FVC) and, consequently, an increase in the forced expiratory volume in one second (FEV1) to FVC ratio after placebo inhalation (p < 0.05), but no changes were found for percent-predicted FVC, FEV1, percent-predicted FEV1, percent-predicted forced expiratory flow (FEF25%-75%), percent-predicted peak expiratory flow (PEF), diffusing capacity of the lung for carbon monoxide (DLCO), single-breath alveolar volume (VA) and DLCO/VA ratio when compared with the baseline. Tiotropium inhalation caused a significant increase in FVC, percent-predicted FEV1, FEV1/FVC and percent-predicted FEF25%-75%, although the decrease in DLCO was insignificant (12.4 +/- 0.9 to 11.4 +/- 0.9). In conclusion, tiotropium does not change the pulmonary-diffusing capacity in healthy volunteers.     

沙美特罗/丙酸氟替卡松对哮喘儿童肺功能的改善及临床意义

目的:观察沙美特罗/丙酸氟替卡松对哮喘儿童肺功能改善情况。方法:采用德国Jaeger公司的MasterscreenIOS测定仪,对61例支气管哮喘患儿在沙美特罗/丙酸氟替卡松治疗前后进行通气肺功能(F-V)和脉冲振荡(IOS)检测。观察用力肺活量(FVC)、第一秒用力呼气容积(FEV1)、最大呼气流速(PEF)、呼出25%肺活量时最大呼气流量(FEF25)、呼出50%肺活量时最大呼气流量(FEF50)、呼出75%肺活量时最大呼气流量(FEF75);呼吸阻抗(Zrs)、气道总阻力(R5)、中心气道阻力(R20)、响应频率(Fres)。结果:沙美特罗/丙酸氟替卡松治疗后FVC、FEV1、PEF均明显升高(P<0.001),而Zrs、R5、R20、Fres均明显降低(P<0.05),两者检查结果均有显著统计学意义。结论:吸入沙美特罗/丙酸氟替卡松能改善哮喘儿童的肺通气功能,降低气道阻力,是治疗儿童哮喘的理想药物之一。     

Effect of oral contraceptives on respiratory function

The present study was carried out to assess the lung functions in oral contraceptive administered women. Lung function tests were carried out with Spirometer (Vitallograph Compact II). A significant increase in vital capacity (VC) was observed in these women as compared to normal control. There was also a significant decrease in forced expiratory volume in 1 sec./vital capacity (FEV1/VC%) and forced expiratory volume in 1 sec./forced vital capacity (FEV1/FVC%) among oral contraceptive administered women as compared to controls. Further, a significant increase in peak expiratory flow rate (PEF), reduction in forced expiratory flow rate (FEF75-85%) and FEF75% were observed among oral contraceptive administered women as compared to controls. The increase in VC and PEF might be due to the synthetic form of progesterone (progestins) present in oral contraceptive pills which causes hyperventilatory changes. Synthetic progesterone during luteal phase of menstrual cycle might increase the static and dynamic volumes of lung i.e. VC and PEF. But FEF75% showed a decrease which might be due to the lower neuromuscular coordination during breathing.     

高原环境肺功能改变对复方新诺明药物动力学的影响

目的：探讨高原低氧条件下肺功能与复方新诺明（sulfamethoxazole Co,SMZ Co）药物动力学的关系。方法：采用高效液相色谱法测定平原、急进高原和久居高原3组2个群体健康汉族男性青年志愿者口服单剂量复方新诺明前后15个时间点血浆药物浓度。应用德国Jegger肺功能仪测定3组肺功能。采用DAS2．0和SPSS13．0统计软件计算3组受试者口服复方新诺明片后磺胺甲噁唑的药物动力学和肺功能参数。结果：急进高原组受试者的药动物力学参数消除速率常数（Ke）、AUC、平均驻留时间（MRT）、半衰期（t1/2）、清除率（CL）与平原组比较差异有统计学意义,久居高原组受试者的药物动力学参数Ke、MRT、t1/2与平原组比较差异有统计学意义,急进高原纽受试者的药动物力学参数t1/2、表观分布容积（V／F）与久居高原组比较差异有统计学意义。急进高原组的呼出25％肺活量时最大呼气峰流速（FEF25％）和最大呼气峰流速（PEF％）值大于平原和久居组（P〈0．01）,久居组呼出50％肺活量时最大呼气峰流速（FEF50％）、最大呼气中段流速（MMEF％）、用力呼气容积（FEV％）,用力肺活量（FVC％）和肺活量（VC％）与急进高原和平原组相比显著下降（P分别〈0．05和0．01）。最大呼气峰流速（PEF％）、FEF50％与AUC正相关;FVC％、PEF％、FEF50％、MMEF％和用力呼气容积占用力肺活量的百分比（FEV／FVC％）与t1/2和VIF负相关。结论：高原环境肺功能改变对复方新诺明药物动力学参数AUC、t1/2,和V/F有显著影响。     

Lung function development in Indian men and women during late adolescence and early adulthood--a longitudinal study

Lung function development was studied in a cohort of Indian men (n = 31) and women (n = 36), over a period of four years during late adolescence and early adulthood. Forced expiratory spirograms and peak expiratory flow rates were recorded at intervals of approximately two years. All volumes and flow rates were higher in men, but volume adjusted flow rates were higher in women. Forced vital capacity (FVC) forced expiratory volume in one second (FEV1) and peak expiratory flow (PEF) were significantly higher in men even after standardizing for age, height and weight. Height and PEF increased significantly in men and women over the four years. Volumes showed a greater increase whereas flow rates and volume adjusted flow rates showed a greater decrease in men. The decline in the forced expiratory flow in the middle half of the FVC (FEF 25-75%) was significantly less in women. These results suggest that although lung size is greater in men, small airway dynamics may be better in young women.     

Single-dose efficacy and safety of zindotrine, a new oral bronchodilator

Zindotrine, a new bronchodilator, may be an alternative to theophylline in treating reversible airflow obstruction. Efficacy and cardiovascular effects of a single 300 mg oral dose of zindotrine were compared with placebo in a two-period, double-blind, crossover trial. Twelve subjects with airflow obstruction reversible after isoproterenol and theophylline completed the trial. Improvement in pulmonary function (forced vital capacity [FVC], forced expiratory volume in one second, and forced expiratory flow rate from 25 to 75 percent of FVC) was greater after zindotrine than with placebo. Pulmonary function tests increased 15 percent or more over baseline in 30 minutes after active drug, lasting up to 6 hours. Mild decreases in heart rate and mean blood pressure occurred after both treatments, with changes equal in both treatment groups. Six subjects had mild subjective side effects after zindotrine (headache, dizziness, vertigo, flushing, and heartburn) compared with one report of lightheadedness after placebo. A single dose of zindotrine 300 mg provides effective bronchodilator action with a relatively prolonged response and tolerable side effects.     

Inhaled dopamine induces bronchodilatation in patients with bronchial asthma.

OBJECTIVE: To determine the probable bronchodilating effect of dopamine administered by inhalation route in patients with crisis of bronchial asthma and the effect of dopamine on bronchial motor tone. DESIGN AND METHOD: We have studied eighteen (18) patients with crisis of bronchial asthma, ten (10) subjects with bronchial hyperreactivity and ten (10) healthy subjects. Patients with other pulmonary or cardiac disease were excluded. All received by inhalation placebo (0.9% saline solution), dopamine at 0.5 microg/kg/min (controlled by heart rate and arterial pressure with a dynamap), and placebo. Respiratory parameters: forced vital capacity (FVC), forced expiratory volume at the first second (FEV1), forced maximal expiratory flow (FEFmax) and forced expiratory flow at the 50% of vital capacity (FEF50) were measured in each protocol period. Student's paired t test, Wilcoxon and Mann Whitney analysis were performed. RESULTS: After dopamine inhalation, there was an increase of FVC by 23% (p<0.001); an increase of FEV1 by 39% (p<0.0001); an increase of FEF50 by 33% (p<0.001) and an increase of FEFmax by 31% (p<0.001). There were no respiratory parameter changes in both, subjects with bronchial hyperreactivity and normal after dopamine inhalation. CONCLUSIONS: Inhaled dopamine induces bronchodilatation in patients with crisis of bronchial asthma. Inhaled dopamine neither alters basal bronchial tone in healthy subjects nor in subjects with bronchial hyperreactivity.     

Pulmonary functions in air conditioner users

Air conditioning may affect human health since it has profound effect on our environment, than just lowering temperature. The present study was planned to assess the effect of air conditioners (AC) on pulmonary functions in young healthy non-smoker males. The study group comprised of ten subjects who were using AC's in their cars for at least 1 hr daily since last 6 months. While ten subjects who did not use AC at all served as controls. The pulmonary functions were assessed using PK Morgan 232 spirometer in a closed room. The peak expiratory flow rate (PEFR) and Forced expiratory flow between 25-75% of vital capacity (FEF25-75) were significantly reduced in subjects using car AC's. Inspiratory flow rates also showed a trend towards decline in AC users but could not reach the level of significance. The lung volumes and capacities were not significantly different in the two groups except for forced expiratory volume in 0.5 sec (FEV 0.5 sec), which also decreased in AC users. The airway resistance and lung compliance did not show significant change. In the presence of normal FEV1, reduced FEF25-75% which is the flow rate over the middle half of vital capacity, is an evidence of mild airflow limitation. The result is suggestive of predisposition of AC users towards respiratory disorders in form of mild airflow restriction.     

Large and small airway responses to procaterol hydrochloride administered through different extension devices in asthmatic patients.

The effects of spacer devices on the magnitude and velocity of large and small airway bronchodilator responses in asthmatic patients who can correctly operate a metered dose inhaler (MDI) remain unclear. According to a double-blinded, randomized, crossover protocol, 14 asthmatic patients were studied on seven separate occasions. On each occasion, patients inhaled doubling methacholine concentrations until forced expiratory volume in 1 second (FEV1) had fallen by 20% of baseline. Changes in forced expiratory flow between 25% and 75% of vital capacity (FEF25-75) were also evaluated. Subsequently, patients were administered 20 or 50 micrograms of procaterol from an MDI either alone or in conjunction with a small- or large-volume spacer device. Changes in FEV1 and FEF25-75 corrected for baseline forced vital capacity (isoFEF25-75) were assessed at 3-minute intervals for 15 minutes and at 30 minutes. Spontaneous recovery was similarly evaluated. The time required to attain significant increases in both FEV1 and isoFEF25-75 was calculated in bronchodilator trials. With 20 micrograms of procaterol, both spacers allowed larger and faster FEV1 increases than the MDI alone (P < 0.01); with 50 micrograms, the velocity and magnitude of FEV1 increases were further enhanced in trials with the MDI alone. The lower procaterol dose via the large-volume spacer determined larger and faster isoFEF25-75 increases than the higher dose via both the small-volume spacer and the MDI alone (P < 0.01). Spacers enhance bronchodilation even in patients using MDIs optimally. Compared with both the small-volume device and the MDI alone, the large-volume spacer allows faster and larger small airway dilation with less than half of the procaterol dose.     

Evaluation of the onset and duration of response to cold air inhalation challenge in cynomolgus monkeys (Macaca fascicularis)

Cold air inhalation challenge (CAIC) for the evaluation of bronchial reactivity has been proposed as a physical agent alternative to chemical agent challenges (methacholine or histamine), especially suitable for the occupational environment. The present investigation describes and evaluates a method for performing cold air inhalation challenge in Cynomolgus monkeys (Macaca fascicularis), a species shown to be useful in animal modeling studies of occupational asthma. Six adult male anesthetized monkeys were ventilated by changes in external pressure while breathing cold air (-25 degrees C to -30 degrees C). Pulmonary function testing was performed at 10, 25, 40 and 55 min post-challenge. Significant increases (P less than 0.05) in average pulmonary flow resistance (RL) and decreases in dynamic compliance (CL dyn) were observed, with maximum impairment occurring at 25 min post-challenge, with a trend towards a return to baseline values at 55 min post-challenge. Peak expiratory flow rate (PEFR), forced expiratory volume in 0.5 s/forced vital capacity (FEV0.5/FVC) and forced expiratory flow at 50% forced vital capacity (FEF50) showed the same general pattern of reduction as seen with RL; however, these results were not statistically significant, most probably owing to individual monkey variability and the small number of monkeys (N = 6) used. A repeat challenge at 25 min after a primary challenge yielded increased RL in one monkey, suggesting that no absolute refractory period is present from CAIC. Results of these studies demonstrate that CAIC causes bronchoconstriction in monkeys and may be useful in further animal modeling studies designed to determine the asthmogenic/airway irritant potential of occupational toxicants.     

Determinants of bronchial hyperresponsiveness in subjects with rhinitis

Subjects with rhinitis but without asthma may have coexisting bronchial hyperresponsiveness, although the reasons for this are uncertain. To evaluate the factors that determine BHR in rhinitis we examined 410 patients with symptomatic rhinitis with forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC)>or=80% of the predicted value. In all subjects a skin prick test (SPT) was performed, a determination of total serum IgE and an eosinophils count in the blood. Of the 410 subjects we found that 161 (39.3%) exhibited a methacholine PD20 of 800 mg or less (Group A), whereas 249 (60.7%) had a methacholine PD20 more of 800 mg (Group B). Despite the matched mean values for FEV1 and FVC, compared with Group B, Group A had a lower predicted forced expiratory flow between 25% and 75%(FEF25%-75%) (86.7 +/- 12.0 vs. 93.7 +/- 7.3, P < 0.0001). A great portion of the subjects of the Group Ain respect to subjects of the Group B were exposed to passive smoke (37.8% vs. 22.0%, P = 0.0008), reported having mothers with asthma (34.1% vs. 6.0%, P < 0.0001), presented a positive skin prick test (93.7% vs. 67.0%, P < 0.0001), had higher levels of total serum IgE (geometric mean of Log10 2.46 +/- 0.27 kU/L vs. 2.06 +/- 0.38 kU/L, P < 0.0001) and higher blood eosinophil counts (geometric mean of Log10 2.67 +/- 0.07 x 10(-3) mL vs. 2.57 +/- 0.09 x 10(-3) mL, P < 0.0001), and reported increased nasal obstruction (2.0 (95% CI 1.8 to 2.2) vs. 0.6 (95% CI 0.5 to 0.7), P < 0.0001). Logistic regression demonstrates that nasal obstruction (OR 2.19, 95% CI 1.72 to 2.80) and the presence of positive SPT (OR 6.15, 95% CI 2.42 to 15.61) were the most available predictors to discriminate between subjects with BHR and subjects without BHR. In addition, BHR was positively related to blood eosinophil counts (OR= 2.80, 95% CI 1.54 to 5.07), FEF25%-75% values (OR= 2.72, 95% CI 1.23 to 5.99) and familiarity (mother) for asthma (OR = 2.45, 95% CI 1.10 to 5.46). Whereas passive smoke and total serum IgE were not positively related to BHR. Increased nasal obstruction and the presence of positive SPT were the most available predictors to discriminate between subjects with and without BHR. Finally, BHR was positively related to blood eosinophil counts, FEF25%-75% values and to familiarity (mother) for asthma.     

Pulmonary hypofunction due to calcium carbonate nanomaterial exposure in occupational workers: a cross-sectional study

Calcium carbonate nanomaterials (nano-CaCO₃) are widely used in both manufacturing and consumer products, but their potential health hazards remain unclear. The objective of this study was to survey workplace exposure levels and health effects of workers exposed to nano-CaCO₃. Personal and area sampling, as well as real-time and dust monitoring, were performed to characterize mass exposure, particle size distribution, and particle number exposure. A total of 56 workers (28 exposed workers and 28 unexposed controls) were studied in a cross-sectional study. They completed physical examinations, spirometry, and digital radiography. The results showed that the gravimetric nano-CaCO₃ concentration was 5.264?±?6.987?mg/m³ (0.037–22.192?mg/m³) at the workplace, and 3.577?±?2.065?mg/m³ (2.042–8.161?mg/m³) in the breathing zone of the exposed workers. The particle number concentrations ranged from 8193 to 39?621 particles/cm³ with a size range of 30–150?nm. The process of packing had the highest gravimetric and particle number concentrations. The particle number concentration positively correlated with gravimetric concentrations of nano-CaCO₃. The levels of hemoglobin, creatine phosphokinase (CK), lactate dehydrogenase, and high-density lipoprotein cholesterol (HDL-C) in the nano-CaCO₃ exposure group increased significantly, but the white blood cell count (WBC), Complement 3 (C3), total protein (TP), uric acid, and creatinine (CREA) all decreased significantly. The prevalence rate of pulmonary hypofunction was significantly higher (p?=?0.037), and the levels of vital capacity (VC), forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC, peak expiratory flow and forced expiratory flow 25% (FEF 25%), FEF 25–75% were negatively correlated with gravimetric concentrations of nano-CaCO₃ (p?3 exposure level was associated with pulmonary hypofunction (p?=?0.005). Meanwhile, a dose-effect relationship was found between the accumulated gravimetric concentrations of nano-CaCO₃ and the prevalence rate of pulmonary hypofunction (p?=?0.048). In conclusion, long-term and high-level nano-CaCO₃ exposure can induce pulmonary hypofunction in workers. Thus, lung function examination is suggested for occupational populations with nano-CaCO₃ exposure. Furthermore, future health protection efforts should focus on senior workers with accumulation effects of nano-CaCO₃ exposure.